Extending the discussion at http://www.adom.de/forums/project.php?issueid=634, it would be cool if NPCs react to how the PC interacts with the environment. Examples:

• Villagers get upset if the PC destroys house walls
• Villagers get upset if the PC chops down village trees
• Villagers laugh at the PC for swimming in the local pond
• Good NPCs show concern (or even try to help) if the PC is drowning
• If the PC builds a bridge across a river next to the village, the villagers could comment on the new convenience

These could even feed into the PC's global reputation, and cause rumours to spread ("Did you hear? There is a madman destroying people's homes!")